Answer:
Bioremediation
Explanation:
Bioremediation means using living organisms to detoxify polluted ecosystems.
The organism that has no specialized cell is Paramecium.
Paramecium are members of the phylum Ciliophora. They feed on organisms like bacteria, algae, and yeasts . These organisms uses cilia to sweep the food along with some water into the cell after it falls into the oral groove. The food then goes through the cell mouth into the gullet.
Choloesterol is present in the membrane. It's role in the membrane is permeability reduction. Cholesteron is also used in corticosteroids synthesis(hormone secreted by the renal glands)
It is the ozone layer, good luck! :)